Reliability Analysis based on Dependent Competing Risk Model of Imperfect Shock Model Considering Changing Threshold and Degradation Process *

In this paper, a dependent competing risk model for a system with two-type failures is studied. Most scholars in present research consider that every shock can cause damage on the degradation process, however, because of the system resistance, only shock loads which are larger than a certain level can cause damage on the degradation. Consider that degradation failure due to degradation process and catastrophic failure due to random shocks will both make the system failed. Assume further that the degradation process and random shocks are not independent. Random shocks resulted in additional degradation. Meanwhile, degradation process affected the hard failure threshold of random shocks. In this case, reliability model of system was built. Furthermore, reliability analysis (independent verses dependent) and sensitivity analysis with different arrival rate were shown. Finally, this paper gave a numerical example. When a component experiences both degradation process and random shocks, this paper not only considers the influence of the random shocks on degradation, but also the impact of degradation on the shocks. On the other hand, this paper considered the situation of incomplete impact and established a competing model of degradation failure and traumatic failure.